This is just an observation... it has taken me years to put this together (and likely this is already known).
If there is a Windows Update *waiting* to be installed with the OS giving reminder messages that are ignored-
ACP Shutdown sequences are at risk. Typically a message like this follows:

Logging to C:\Users\Pomenis\Documents\ACP Astronomy\Logs\20210416\20210417@105801.log
Initializing AcquireSupport V8.1.1
User actions detected.
>> NOTE: User actions for optional Alt-Az targeting are in effect.
Telescope is ACP->Driver for telescope connected through TheSky
There was a problem initializing the support library:
The telescope is not connected.

This has happened across all computers I have used and also regardless of whether there are useractions in play or not.
This also occurs regardless of what driver ACP is talking to. (This would occur on the Schulman Telescope with its custom
ASCOM (LCOGT) driver).

Its the weirdest thing. Solution, of course, install the updates/reboot the computer.
I do not think there is a computer uptime (counter) issue- but maybe uptime *and* updates are both necessary to trigger this.

A minor thing...but it just happened to me last night ( I ignored the Window's update and said remind me later... and ta da... no shutdown at request.)